Abstract

The prey composition and the consumption/biomass ratio (Q/B) of Chilean hake, Merluccius gayi, are described for the period 1992 to 1998 off central-south Chile (34° to 40° S). Chilean hake is a combination of benthic, demersal and pelagic predator.The food items were euphausiids (31.2 % by weight), Galatheidae squat lobsters (21.8 % , other Crustacea (1.1 %), clupeiforms (11.2 %), cannibalism (27 %), and other teleosts (7.9 %). The more important changes in the diet of hake were the notable clear presence of the squat-lobster Cervimunida johni (from the third quarter of 1996 to the third quarter of 1997), the virtual absence of both species of squat lobster, C. johni and Plueroncodes monodon in 1998, the absence of jack mackerel Trachurus symmetricus murphyi from 1996 to 1998, and the clear presence of Patagonian grenadier, Macruronus magellanicus, in the fourth quarters of 1993, 1997 and 1998. An estimate of Q/B = 1.35 % (daily) was obtained by using an equilibrium age-structured model. This value was similar to the estimates based on empirical models (i. e. 0.919 to 1.132 %). It was concluded that Chilean hake is a predator of importance on benthic, demersal and pelagic communities off central-south Chile.